Recently, an LED light having high luminance, comparable to that of a lighting device such as an incandescent lamp, while being driven with low power has attracted increasing attention. Particularly, light driving devices for driving the LED light by controlling uniform current to flow through the LED light are actively researched and developed.
Such a light driving device has various lighting functions and, particularly, can enable lighting in various forms by changing dimming levels of LED elements arranged in serial/parallel connection.
In general, a light driving device can include a rectification circuit for rectifying full waves output from an AC power supply, a transformation circuit for transforming the voltage output from the rectification circuit and outputting the transformed voltage, a power factor correction circuit for correcting a power factor of power output from the AC power supply by controlling the output voltage of the transformation circuit, a smoothing circuit for smoothing the voltage output from the transformation circuit to output a stable DC voltage and supplying the output voltage to an LED module, a constant current driving circuit for controlling LED current such that uniform driving current flows through the LED module, and a dimming control circuit for controlling current flow in the LED module by controlling the constant current driving circuit according to PWM (Pulse Width Modulation), thereby controlling dimming.